CVE intelligence and bounded remediation

CVE-2021-21278 — RSSHub is an open source, easy to use, and extensible RSS feed generator

Critical CVSS 9.8

RSSHub is an open source, easy to use, and extensible RSS feed generator. In RSSHub before version 7f1c430 (non-semantic versioning) there is a risk of code injection. Some routes use `eval` or `Function constructor`, which may be injected by the target site with unsafe code, causing server-side security issues The fix in version 7f1c430 is to temporarily remove the problematic route and added a `no-new-func` rule to eslint.

Severity
Critical
CVSS
9.8 (3.1)
Published
2021-01-26
CISA KEV
Not currently listed
Ecosystem
software/application
Weaknesses
CWE-74

Affected products

  • rsshub / rsshub

Matched remediation archetype

Command, code, expression, and template injection

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Check exposure

  • Trace untrusted values to process execution, interpreters, evaluators, template engines, dynamic imports, and administrative scripting features.
  • Determine whether the affected path is reachable across each trust boundary and which service account or host privilege it inherits.
  • Review configuration for optional execution features, unsafe compatibility modes, and shell invocation.

Remediate safely

  • Replace string-built commands or evaluated code with fixed operations and structured argument APIs that do not invoke a shell.
  • Use strict allowlists for operation identifiers and reject unexpected input before it reaches any interpreter.
  • Update the affected component and add inert regression tests covering metacharacters, encoding variants, and alternate request paths.

Authoritative sources

Complete CVE record and remediation plan

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